Arduino uno & ethernet shield W5100 (wasnt online yet)

[PeteKnight]

The sketch has quite a few issues, some of which I’ve pointed-out before…

Issue 1, you’re assigning V1 as an alias for two different widgets, and LCD and LED…

@Metin_Tataroglu

WidgetLCD lcd(V1);

@Metin_Tataroglu

WidgetLED led1(V1);

Issue 2, these two lines of code are partly responsible for ensuring that the Ethernet interface is active, and the SD card is inactive (The two cant operate at the same time). As a result, they shouod be BEFORE your Blynk.begin command…

@Metin_Tataroglu

  pinMode(SDCARD_CS, OUTPUT);
  digitalWrite(SDCARD_CS, HIGH); // Deselect the SD card

Issue 3, The Blynk server is notifying you of a change in the value of the (slider) widget attached to V5. You are then immediately writing this change back to pin V5. I’ve asked you before why you are doing this and you’ve failed to answer. You need to remove the Blynk.virtualWrite command from this BLYNK_WRITE function…

@Metin_Tataroglu

BLYNK_WRITE(V5)
{
 SET_TEMP = param.asInt();
 Blynk.virtualWrite(V5,SET_TEMP);
}

Issue 4, You are writing the TEMPERATURE variable to Pin V5 BEFORE you’ve taken the temperature reading…

@Metin_Tataroglu

void sendUpTEMPERATURE()
{
  
Blynk.virtualWrite(V10, TEMPERATURE);        <<<<<< You've not taken the yeading yet!
 
INCOMING_DATA = analogRead(LM35);
VOLTAGE = (INCOMING_DATA / 1023.0) * 5000;
TEMPERATURE = VOLTAGE / 10.0;                 <<<<<<<< Now you have

Issue 5, In this if statement you are attempting to check if the (button?) widget attached to pin V15 is LOW. However, you can’t do this. V15 is an alias that allows you to refer to a virtual pin, and if you try to print it’s value you’ll see that it is always 15 (and V16 will always be 16 etc).
You need to make the pinvalue variable in BLYNK_WRITE(V15) global (and preferable give it a more sensible name) than use that variable in your if statement…

@Metin_Tataroglu

if ((SET_TEMP < TEMPERATURE) || (V15 == LOW)){

You also do the same thing elsewhere in your sendUpTEMPERATURE function.

Once you’ve fixed these issues then I’d suggest that you delete the QuickStart device and template using the web console.
Then, create a new template and add-in the virtual datastreams that you require. These appear to be V1, V5 and V15 (and possibly another one that will be for your LED which currently seems to be sharing pin V1 - see Issue 1 above).
Give these appropriate min/max values and data types (Integer or Double) then create a device based on this template.
In the Device > Device Info screen copy the Firmware Configuration and paste ot at the top of your sketch.

Then, in the app, add widgets to this device dashboard and configure them correctly.

In your sketch you should change this:

[quote=“Metin_Tataroglu, post:50, topic:42269”]

BLYNK_CONNECTED() {
  Blynk.syncAll();
  
}

so that instead of Blynk.syncAll(); you use Blynk.syncVirtual(V5);

You also need to comment-out this line…

@Metin_Tataroglu

Blynk.notify("ODA ISISI ÇOK DÜŞÜK, KONTROL ET!!");

Once you have it working, you should read this about how to send notifications in Blynk IoT…

Events, Notifications and the use of "Flag" variables

Update 19th May 2022 - you’ll see references to a limit of one event per minute in this tutorial. It appears that this limit has now been removed. I’ve not yet tested this myself, and when I do I’ll update the tutorial to reflect my findings. I’m seeing quite a few posts from people who are finding it difficult to get notifications working in Blynk IoT, and who don’t understand how to use “flag” variables to limit the number of notifications that are sent for any given alert situation. I thoug…

Pete.